Wouldn't those addicted to microtransactions just make another account when they can't buy anything on their main account?
The idea of a microtransaction is that it stays on and is used by an account. It isn't the buying that's the addiction, it's the having.
Purchasing another copy of the game isn't just bypassing their self-imposed limit, it's resetting. This is also why I proposed the abstainer-specific banner and ranks.